1. Technical Field
The present invention relates to an apparatus for depositing an organic material on a substrate. More particularly, the present invention relates to an apparatus for depositing an organic material droplet on a substrate.
2. Discussion of the Related Art
Generally, a display apparatus displays an image using data processed by an information processing apparatus.
The different types of display apparatus include a cathode ray tube (CRT) apparatus, a liquid crystal display (LCD) apparatus, an organic light emitting diode (OLED) apparatus, a plasma display panel (PDP), etc. The CRT displays an image by controlling an electron beam applied to a fluorescent layer. The LCD displays an image by orienting liquid crystals. The OLED displays an image by currents that flow through an organic light emitting layer. The PDP displays an image by plasma.
The OLED has features such as being thin in thickness, high luminance, full color, low power consumption, and low manufacturing cost, etc.
The OLED includes an anode electrode arranged in a matrix shape on a substrate, an organic layer formed on the substrate and having an opening through which a portion of the anode electrode is exposed, an organic light emitting layer formed on the anode electrode exposed by the organic layer, and a cathode electrode formed on the organic light emitting layer.
The organic light emitting layer of the OLED includes a hole injection layer (HIL), an emitting material layer (EML) and an electron injection layer (EIL).
The organic light emitting layer can be formed by processes such as a slit mask, a spin coating, a roll-to-roll, a vacuum deposition, etc. Recently, a dropping method is employed, wherein a droplet of an organic material is dropped into a cavity formed at the organic layer.
An apparatus for dropping a droplet of an organic material typically includes an organic material dropping unit and a transfer unit which transfers the organic material dropping unit. In the conventional apparatus, injecting the organic material at once into the cavity arranged in a matrix shape may be difficult. The conventional apparatus scans organic material cavities and injects the organic material into the cavities as the dropping unit traverses along the layer.
When a drying time of the organic material injected into the cavity is different, the organic light emitting layers of each cavity have a profile different from each other and light generated from an organic light emitting layer may have different luminance. Therefore, display quality is deteriorated.
Recently, an apparatus is used for simultaneously dropping organic materials along a layer to form a more uniform light emitting layer.
Such apparatus uses a plurality of organic material dropping units and a plurality of transfer units. The transfer units correspond to the organic material dropping units. However, such apparatus of dropping the organic material is larger in size.